966 
§ 10. Anhydrous manganese sulphate. All the water was driven 
out of the salt by heating. 
The results are given in Table VIII. 
With anhydrous manganese sulphate another divergence from the 
law of Curie over the whole field of low temperatures was found. 
Down to nitrogen temperatures, however, it is only a disturbance 
of the first kind. At hydrogen temperatures a further disturbance 
shows itself which is not unlike the disturbances with solid oxygen, 
and at any rate belongs to a kind of disturbances that we have not 
yet been able to reduce to a definite type. It is remarkable that 
just as with crystallized ferrous sulphate the presence of molecules of 
water of crystallization causes a diminution of the quantity A’ to a 
very small value in comparison with that of the anhydrous sub- 
| TABLE VIII. 
Anhydrous manganese sulphate MnSOQ,, (1). A= 240, | 
7 y.10° \4(THA/)10f Limits of H Bath 
| Bee) E 
| | 
203°.9 K. | 87.8 | 27910 | 6—I7 kilog. | Air. | 
169.6 | 144.2 27920 | BAT Liquid ethylene. 
TE | 274.8 | 27870 | 
; | | |) 5—16 | Liquid nitrogen. 
64.9 314.5 27960 
20.1 603 _ 26590 | | 
17.8 627 26210 | 4—16 Liquid hydrogen. | 
14.4 636 | 24420 | | 
stance, here too A’ becomes less by the addition of molecules of 
water of crystallization, and to such a degree, that, if one does not 
go below nitrogen temperatures A’ appears to have become = 0, 
whereas with anhydrous salt 4’ = 24°. 
If we calculate the number of magnetons for the crystallized 
salt with C—=y7(A'=0) and for the anhydrous with C’ = y(7-+A’) 
and with A’ = 24°, we find the same number of magnetons in both 
cases, viz. 29. This is one less than is found in the solution *). 
1) P. Weiss, Journal de physique, 1911, p. 976. 
